Safety shot-firer



UNITED STATES CHARLES FU'KUZO OAKA, OF LOVETTVILLE, ALBERTA, CANAD.

SAFETY snor-FIBER.

Specification of Letters Patent. Patented hay 10, 1921.

Application led April 29, 1920. Serial No. 377,632.

To all whom t may concern.'

Be it known that I, Ci-iAizLns FUKUZo Gana, a subject of the King of Great Britain, a resident of the town of Lovettville, Province of Alberta, Dominion of Cana-da, have invented certain new and useful lmprovements in Safety Shot-Firers, of which the following is a specication.

This invention relates toimprovements in a portable safety shot irer, designed for use in mines and quarries, in conjunction with any suitable type of storage battery at present used (in mining operations), and the objects of the invention are to prevent premature firing, to so control the rer 'that it is automatically locked in an inoperative position during'the fixing of the connections of the electric ciicuit of which the irer forms a part, to permit of the lirer being actuated only when the locking mechanism has been released, so that the firer cannot be actuated unintentionally, because two operations are necessary one to unlock the rer, and the other to positively close the circuit by manually operated means before a shot can be detonated.

Further objects are to facilitate mounting the irer on a belt so that it will be carried about by the wearer and always in position to complete an electric circuit, to inclose vthe several working parts whereby they are not likely to be interfered with, but at the same time allowing of ready access for inspection and repair, and generally to adapt the firer to better perform the functions required of it.`

For a better understanding of myv invention, reference is made to the accompanying drawings illustrating an embodiment of the saine and in which:

Figure 1 is a perspective view of the shot rer as seen when lying latf Fig. 2 is a rear elevation of the shot firer with the cover removed to show the mechanism housed within the casing.

Fig. 3 is a perspective view of the mechanism inclosed in the casing, and as seen when occupying a position similar to that shown in Fig. 1.

Fig. 4 is a transverse section onthe line 4--4 of Fig. 2, the back cover however beingin position.

ig. 5 is a section on the line 5-5 of Fig. 4.

Like characters of reference refer to like parts in the several figures.

Referring to the drawings: A represents the improved shot rer comprising a casing 10 openV at the rear and provided with al are provided with posts 18 and 19, which extend into the interior of the casing.

" The posts 18 and 19 are insulated from the casing 10 by suitable washers 20 and 21.

Rigidly secured to the bottom of the casing 10 is a. block 22 of insulating material, which is of angleshape in longitudinal section, and is provided at one end with a pair of posts 23 and 24, which are spaced apart and thus not in electrical contact with each other anden the upper end of the said posts switches 25 and 26 are pivoted.

Gn the opposite ends ofthe insulating block 22 to thev posts 23 and 24 a pair of contact members 27 and 28 are mounted, the said contact members being provided with posts 29 and 30.

The switches 25 and 26 are connected by a transversely extendingjmember 31 of -insulating material which is provided on the upper face with a bracket 32 provided with a pair of upwardly extending` spaced jaws 33 having longitudinally extending slots 34 therein, and this bracket is spaced from the switches 25 and 26 and thus does not make any electric contact therewith.

A cylinder 36A depends' from the upper wall of the casing into the interior thereof, and a casing 37 is arranged longitudinally on 'the outer face of the upper wall of the casing 10. A plunger 38 passes through a portion of the casing `37 into the cylinder 36, and is provided at the lower end with a transversely extending pin 39 which engages with the slot 34 in the jaws of the bracket 32.

The plunger 38 is embraced by the spiral spring 41,V which is located in the cylinder 36, the lower end of the spring engaging the lower end of the cylinder, and the upper end of the spring engaging with a collar 42 which is fixed to the plunger 38.

That portion of the plunger 38 normally located within the easing 37 is provided with a peripheral l-shaped notch 43, and the upper end ofthe plunger 38 terminates in the thumb or finger grip 44.

A. locking rod 45 is slidably mounted l0ngitudinally within the casing 37, and is formed with an offset end 46 which extends through the slot 47 in the said casing, and this locking roid is provided with a collar 48 between which and the end wall 49 of the said casing a spiral spring 50 is located.

This spring 50 encircles the locking rod 45, and the end of the locking rod is beveled to engage with the V-shaped notch 43 in the plunger 38.

Y On the onevend wall of the casing a con- Yduit GOis provided through which the wires 51 and 52 pass, and the wire 51 is attached to the post 23, while the wire 52 is attached to: the post 24.

The post 29 is connected by a wire 53 to one of the posts 18, and the post 30 is con nected by a wire 54 with one of the posts 19.

The assembly of the rer will be readily understood from the foregoing description.

When the tirer lis to be used, the user passes his belt through the channel me1nbers 13 and thus secures the firer in a suitable position, and thus the operator carries the rer about with him, and there is no possibility of the said iirer becoming lost or misplaced, but will always be in the desired position ready for use.

lVhen a shot is ready for firing, connections are made by the wires 51 and 52 with a cap which is to detonate the shot. The operator now takes the two wires leading from his battery andengages one wire with the V-shaped contact 16 and engages the other wire with the V-shaped contact 17 an electric circuit is now completed and the closing is controlled by the switches 25 and 26.

When everything is ready for the shot to be fired, the operator retracts the locking rod 45 by engaging the thumb of his left hand with the offset end 46 and pulling the locking member longitudinally within the casing 37 thereby disengages the point of the said locking rod from the V-shaped recess 43 in the plunger 38.

This movement releases the plunger 38 which may then be depressed by the operator'applying pressure to the head 44 of the plunger, so moving the plunger within the casing 10 until the switches 25 and 26 engage with the contacts 27 and 28.

In this way the gap between the posts 23 and 24 and the contacts 27 and 28 is bridged, and an electric circuit is completed whereby a spark will be delivered to the cap attached l/Vhen the locking rod 45 has been releasedit is moved longitudinally to rengage the point with the V-shaped recess 43 in the plunger 38.

F rom the above description, it will be seen that I have invented a shot frer which is extremely simple in construction and is fool proof, because it prevents a shot being accidentally fired, and the irer is positively locked in position and requires to be intentionally operated before an electric circuit can be closed by means of the same. y

As many changes could be made inthe above construction and many widely different einboidiments of my invention within the scope of the claims, constructed without departing from the spirit or scope thereof, it is intended that all matter contained in the accompanying specification and drawings shall be interpreted as illustrative and not in a limiting sense.

What I claim as my invention is:

1. A shot tirer comprising a casing, a pair of posts in the casing, a pair of contacts spaced from the posts, arms pivotally mounted to the posts and designed to bridge the f rap between the posts and the contacts, an insulating member connecting the arms, a bracket on the insulating member, a plunger coacting with the bracket, the plunger being manually actuated in one direction, and resilient means for automatically actuating the plunger in the opposite direction. 2. A shot iirer comprising stationary and movable contacts, an insulating bridge connecting said movable contacts and provided with a pair of spaced slotted jaws, and an actuating member for the movable contacts fitting between said jaws and provided with extensions engaging in the slots in the jaws. In witness whereof I have hereunto set my hand in the presence of two witnesses.

CHARLES FUKUZO OAKA. Witnesses E. I-I. MACGREGOR, D. F. ROY. 

